French fries are a staple for many, but traditional deep-frying loads them with excess oil and calories, contributing to long-term health concerns like obesity and hypertension. Researchers at the University of Illinois Urbana-Champaign have found a potential fix: combining microwave energy with classic deep-frying to make healthier, crispier fries.Testing the microwave methodLed by professor Pawan Singh Takhar and doctoral student Yash Shah, the research team focused on reducing oil absorption without sacrificing the crunch and flavor people expect. Working alongside scientists at Washington State University, they tested a specialized unit capable of microwave frying at two different frequencies: 2.45 gigahertz and 5.8 gigahertz.How oil gets trapped insideThe team rinsed, peeled, blanched, and salted potato strips before frying them in 180°C soybean oil. Throughout the process, they measured internal pressure, moisture, temperature, and oil absorption to understand how oil sneaks into the potato during cooking. Oil absorption comes down to internal pressure. Frying creates steam, leaving behind microscopic empty pores. As this water vapor escapes, it causes a drop in internal pressure, creating a vacuum effect that sucks oil into the potato. The researchers discovered that up to 90% of the conventional frying process occurs under this negative pressure. 
Why do microwaves block oilMicrowaves change this dynamic by heating the potato from the inside out rather than relying solely on surface heat. This rapid heating causes water molecules to vaporize much faster, creating positive pressure that pushes outward and blocks oil from entering the potato’s inner pores.The hybrid solutionWhile microwave frying alone cooks potatoes faster and reduces fat intake, it leaves the fries soggy. To fix this, the researchers used mathematical modeling and lab tests to develop a hybrid approach: using conventional frying to create a golden, crispy crust alongside microwave heating to keep oil out and speed up cook times.All about the new tech!The findings were published across two papers in the Journal of Food Science and Current Research in Food Science. Because the required microwave components are cheap and widely available, the team notes that industrial continuous fryers could easily be retrofitted for commercial production.
